This invention is related to the field of desktop and rack-mounted libraries that store removable storage media cartridges.
Small storage libraries are often designed to be mountable in nineteen-inch racks. Rack mounting places several restrictions on the internal layout of the library. For example, routine access to the interior of the library is limited to the front side of the library. Interior access through the library sides is usually blocked by the rack cabinet. Access through the top or bottom sides is often blocked by other equipment mounted in the rack. As a result, small storage libraries requiring only a few storage media cartridges usually position the cartridges in cartridge slots along the front side of the library. From this position the storage media cartridges are readily accessible to a user and their labels can be easily viewed. The cartridge slots are designed to permit storage media cartridge insertion and removal through the side of the cartridge slot facing the user. Side access to the cartridge slots helps keep the height of the library low since no space above or below the cartridge slots is required to accommodate the storage media cartridges or the user""s hands. Robotic mechanisms and cartridge handling devices, such as read-write media drives, read-only drives, and transfer ports (a mechanism used to import and export cartridges from the library) do not require routine access thus they are typically positioned in the middle or back of the library. Positioning these devices further back in the library also helps keep their moving machinery out of reach of the user thus reducing the probability of injury.
To increase the capacity of the storage library, the number of storage media cartridges held in the storage library is typically increased. Three different configurations have been used to accommodate additional cartridges within the rack-mount width constraint. In the first configuration, two rows of cartridge slots, one on top of the other, are provided at the front end of the library. Label viewing is accomplished through a window or door at the front of the library. Storage media cartridge insertion and removal are performed through the front side of the cartridge slots. This first configuration, however, requires a tall housing to accommodate the top row of storage media cartridges.
In the second configuration, the additional storage media cartridges are positioned in a second row on the same plane as, and behind the front row of storage media cartridges. An example of this configuration can be seen in U.S. Pat. No. 5,892,750, issued to Barkley et al., on Apr. 6, 1999. Barkley discloses a library having ten cartridges held in a removable magazine positioned at the front of the housing. Five additional cartridges are stored in a back row next to the drive. This approach keeps the library height low, but the second row is hidden behind the first row. The user must rely on the robotic mechanism to carry the desired cartridge between the second row and a xe2x80x9cmailboxxe2x80x9d at the front of the library. Alternatively, the user must physically remove the front row of storage media cartridges to see and access the cartridges in the second row. Both approaches for reaching the second row are slow, and reliance on the robotic mechanism leaves the storage media cartridges in the second row vulnerable to mechanical and electrical failures.
The third storage library configuration positions all of the storage media cartridges in a row perpendicular to the front of the library. This configuration takes advantage of the greater depth than width of the library to accommodate more storage media cartridges. An example of this configuration is disclosed in U.S. Pat. No. 5,870,245 issued to Kersey et al., on Feb. 9, 1999. Storage media cartridge insertion and removal are typically accomplished using a removable magazine. (Overall, magazines are undesirable for cost, schedule and maintenance reasons.) Labels can only be read while the removable magazine is outside the storage library. After the removable magazine has been installed in the storage library, the user has no direct means to view or access the storage media cartridges.
Positioning the robotic mechanism, cartridge handling devices and other components out of reach and out of sight from the user has advantages from a safety point of view, but has several disadvantages from a maintenance point of view. When the robotic mechanism is hidden from view and it is not operating properly, then the user must remove the housing from the rack and open it to inspect the robotic mechanism. Repair or replacement work that must be performed on any component not positioned near the front of the housing also requires the storage library housing to be removed from the rack and opened. Even if the component is accessible from the front side of the storage library, the user must see and work through a short opening, usually less than seven inches tall.
Another problem facing the user of the small storage library occurs when the robotic mechanism jams a storage media cartridge while trying to insert that cartridge into a cartridge slot or cartridge handling device. The robotic mechanism itself, and other components nearby sometimes makes it impossible to free the jammed storage media cartridge by reaching in from the front of the library. Again, the library must be removed from the rack and the housing opened to provide the necessary clearance to fix the problem.
The present invention is an automated storage library suitable for rack-mount and desktop installations. Storage media cartridges and a robotic mechanism that transport the storage media cartridges internal to the library are mounted on a moveable drawer. With the drawer at an internal operating position, the robotic mechanism transports the storage media cartridges between cartridge slots mounted on the drawer and read-write media drives and other cartridge handling devices not mounted on the drawer. The drawer is capable of moving through an opening in the storage library housing to an external position. Movement to the external position allows for easy access to the robotic mechanism and all of the storage media cartridges no matter how the storage media cartridges are positioned with respect to the robotic mechanism. Movement to the external position also allows top insertion and removal of the storage media cartridges from the cartridge slots while maintaining a low storage library height. The drawer may be detachable from the housing to allow unobstructed access to the other components positioned in the interior of the storage library.
During normal operations the opening in the housing is covered by a door to prevent human injury by the robotic mechanism. The door may be pivotally attached to the housing or fixed to the drawer. Attaching the door to the housing allows the door to be opened while the robotic mechanism is in motion. During maintenance operations the open door allows the user to watch the robotic mechanism cycle through its tasks.
In another embodiment, the cartridge slots that hold the storage media cartridges are part of a removal magazine attached to the drawer. The magazine allows for rapid installation and removal of several storage media cartridges at a time. A bar code reader may be mounted on the robotic mechanism or the drawer to support automatic inventory of the storage media cartridges.
Accordingly, it is an object of the present invention to provide a storage library where the robotic mechanism and all of the storage media cartridges are mounted on a drawer that is moveable to the exterior of the storage library where they are readily accessible to the user. Preferably, installation and removal of the storage media cartridges are performed through the top of the cartridge slots that hold the storage media cartridges.
Another object of the present invention is to provide a storage library where the front end of the cartridge handling devices are accessible to the user through the front side of the storage library after the robotic mechanism and storage media cartridges have been moved to the exterior of the storage library.
These and other objects, features and advantages will be readily apparent upon consideration of the following detailed description in conjunction with the accompanying drawings.